Alkylamine as an antimicrobial agent in ophthalmic compositions

ABSTRACT

A multi-purpose contact lens care solution having high activity against fungi and certain bacteria comprising, in liquid aqueous medium, an alkylamine having the following formula, 
     
       
         
         
             
             
         
       
         
         
           
             where R1 is a C 13-17  alkyl, and R2 and R3 are each independently H or —CH 3 , and a non-ionic surfactant. The solution may optionally also include additional antimicrobial components, a buffer component, a viscosity inducing component, a surfactant, taurine, propylene glycol and/or a tonicity component. This solution additionally prevents losses in ocular tissue membrane integrity during contact lens wear.

BACKGROUND OF THE INVENTION

1. Area of the Art

The present invention relates to compositions and methods for eye andcontact lens care. More particularly, the invention relates toophthalmic compositions which contain an alkylamine as a decontaminatingagent for preservation of the solution and/or disinfecting contactlenses.

2. Description of the Prior Art

Contact lens wear induces adverse changes in ocular tissues and the tearfilm. These changes include cornea lactic acidosis and subsequent corneaswelling as a consequence of hypoxia induced by low oxygen gastransmission, changes in corneal epithelial tissue thickness, changes incorneal epithelial and endothelial cell morphology, epithelial surfacecell exfoliation, hyperemia (red eye), adverse changes in corneal andconjunctival cell membrane integrity and destabilization of the tearfilm. Changes in cell membrane integrity can be measured clinically viameasurements of lactate dehydrogenase enzyme release, fluoresceinbarrier permeability or other methods. Corneal epithelial cell membraneintegrity is believed to be critical to maintain a tissue barrierfunction to prevent ocular infection.

Adverse changes in ocular tissues during contact lens wear also mayarise due to exposure of ocular tissues to preservatives, disinfectingagents, cleaning agents and other components in the contact lens caresolutions. This can occur through tissue contact with solutions whichmay directly contact ocular tissues during application or tissue contactwith solutions which may adsorb or absorb to the contact lens duringtreatment of the contact lens by the solution, and subsequently desorbfrom the contact lens during wear into the eye.

Contact lens solutions have become complex formulations of multiplecomponents which provide several functions. Attempts have been made toameliorate the adverse effects of contact lenses and contact lens caresolutions on ocular tissues, with mixed results. The best examples ofsuccess in changing contact lens care solutions to ameliorate theiradverse effects on ocular tissues is represented by the creation ofpolymeric contact lens disinfecting agents, antimicrobial systems whichdo not bind to contact lens surfaces and the inclusion of water-solublepolymers and electrolytes such as potassium chloride, magnesium andcalcium chloride into contact lens multi-purpose and rewettingsolutions. However, despite these favorable changes in the compositionsof contact lens care solutions, none provide perfect in-eye performancewithout some measure of adverse effect on ocular tissues. Some degree ofcompromise to the tear film, tissue or cellular membrane integrity, suchas corneal epithelial cell membrane integrity, remains with all currentcontact lens care solutions. To date users have shown some preferencefor the polymeric quaternary ammonium systems, which combine three stepsof cleaning, disinfecting and rinsing in one. However, such systems areusually weak in anti-fungal activities. Moreover, because of thepositively charged nature of the quaternary ammonium, they tend to beheavily adsorbed or bound to the contact lens materials (which areusually negatively charged), causing eye irritation. Therefore, exists aneed to improve contact lens care products to provide for simpler usewith higher antimicrobial potency and less cornea irritation.

It is desirable to formulate a system having stronger anti-fungalproperties than known systems, without increasing the adverse effects ofcontact lenses and contact lens care solutions on ocular tissues.

Unhoch et al., in U.S. patent application Ser. No. 2003/0189013 A1,entitled “Treatment of Circulating Water Systems,” discloses acomposition consisting of a mixture of polymeric biguanide and analkylamine adjuvant for inhibiting the growth of or killing algae in are-circulating system. The alkylamine has the following structure:

where R2 and R3 are each independent H or optionally substituted C₁₋₄alkyl, and R1 is an optionally substituted C₈₋₁₂ or C₁₈₋₂₂ alkyl.Notably, Unhoch describes the alkylamine as an ‘adjuvant’ useful inre-circulating water systems, as opposed to an antimicrobial.Furthermore, an antimicrobial activity test against a five-microbialpanel (as required by US FDA for contact lens disinfection) shows thatdodecylamine (R1=C₁₂; R2, R3=H), having an antimicrobial activity farless than a more conventional cationically charged quaternary ammoniumcompound such as cetylpyridinium, is not qualified as a disinfectant forcontact lens care.

A significant difference between contact lens care systems andre-circulating water system is that the former requires that a largeamount of surfactant be present as a cleaning agent, while the latter isnot compatible with surfactants due to foaming problems. Anionicsurfactants and polymeric/non-polymeric quaternary ammonium formprecipitate in aqueous solutions and, therefore, cannot be mixed. Thepresence of a non-ionic surfactant at a cleaning agent level usuallywould cause a significant, if not complete, loss of antimicrobialactivity for non-polymeric quaternary ammonium or alkylamine. In fact, anon-ionic surfactant is commonly used in microbiology tests to stopquaternary ammonium/alkylamine activity during tests. Unhoch furtherteaches by implication that alkylamines with R1=C₁₃₋₁₇, which includestetradecylamine, cannot be used in the polymeric biguanide/alkylaminemixture in a recirculating water system since they are insoluble inwater. See, e.g. Experimental section and Table 4. Thus, the Unhochreference does not teach or suggest that the claimed class ofalkylamines would be useful in association with the cleaning of contactlenses.

In view of known limitations with contact lens care compositions, itwould be advantageous to have contact lens care compositions, andmethods of using the same, which are simpler to use, have higherantimicrobial potency, and show less corneal irritation.

DETAILED DESCRIPTION

New compositions for treating contact lenses have been discovered. Thepresent compositions include, in an aqueous liquid medium, a non-ionicsurfactant and an alkylamine having the following formula:

where R1 is a C₁₃₋₁₇ alkyl, and R2 and R3 are each independently H or—CH₃. In an alternate embodiment of the present invention, R1 is aC₁₆₋₁₇ alkylamine, and R2 and R3 are each independently H or —CH₃. Byway of example, when R1 is C₁₄, and R2 and R3 are H, the alkylamine ismyristylamine, and when R1 is C₁₆, and R2 and R3 are H, the alkylamineis cetylamine.

Solutions according to the present invention may also include one ormore of the following: additional antimicrobial components, preferablyreduced in concentration from the concentration that is typically usedwith only one antimicrobial component; a buffer component in an amounteffective to maintain the pH of the solution within a physiologicallyacceptable range; an effective amount of a viscosity inducing component;a surfactant in an amount effective to clean a contact lens contactedwith the solution; and/or a tonicity component in an amount effective toprovide the desired tonicity to the solution. The solutions may alsoinclude taurine. The benefits of including taurine are disclosed in U.S.patent application Ser. No. 10/328,641, to S. Huth, entitled “ContactLens Care Compositions, Methods of Use, and Preparation which ProtectOcular Tissue,” which is incorporated herein by reference. Suchsolutions provide the desired antimicrobial activity and performanceeffectiveness and, importantly, substantial, preferably enhanced, lenswearer/user comfort and acceptability benefits.

Specifically, it has been found that alkylamines having the followingformula,

where R1 is a C₁₃₋₁₇ alkyl, and R2 and R3 are each independently H or—CH₃, has a high activity against fungi and certain bacteria. Such anapplication is hindered due to such alkylamines' lack of solubility inwater. Based on the factors described below, the above-referencedalkylamine may be present in an amount in the range of about 0.1 ppm orabout 0.3 ppm to about 7.5 ppm or about 10 ppm.

There are several obstacles which prevent the use of such antimicrobialagents in contact lens cleaning disinfecting application. First, contactlens cleaning and disinfecting solutions always contain significantamounts of surfactants in order to clean the contact lens surface whichis contaminated mainly by tear protein and lipids. Of the three types ofsurfactants, nonionic surfactants are commonly used for contact lenscleaning. However, these are also commonly used to neutralizequaternary-based antimicrobial agents in microbiology test labs. Thus,the concentration must be carefully controlled.

Anionic surfactants such as soap are generally not compatible withquaternary amine based antimicrobials that are positively charged. Inother words, it is common wisdom that the application of anionicsurfactants would defy the microbial activity of non-polymeric basedpolyquaterniums. Electrostatic interaction between ion of the surfactantand cation of the quaternary ammonium would neutralize the net charge,eliminate the antimicrobial activity and form precipitate due to theloss of hydrophilicity by charge neutralization.

Cationic surfactants are compatible with alkyl amines, but theythemselves are antimicrobial agents, and therefore cannot be added insufficiently large amounts to dissolve the alkyl amine withoutirritating the eye. The inventors have unexpectedly discovered thatalkylamines, especially those that are generally insoluble in water, arehighly active in specific concentration ranges and can be used incontact lens disinfecting. That is, such alkylamines can be used forcontact lens disinfection, provided that they are used with a certaintype of surfactant which functions as a solubilizing agent, and the twoare used according to a special mixing ratio. The inventors have furtherdiscovered that a certain type of non-ionic surfactants, used in acertain mixing ratio, can dissolve these water insoluble alkyl amineswhile maintaining anti-microbial effectiveness for disinfection.Furthermore, such contact lens disinfecting activity is significantlyincreased if polymeric quaternary amine such as Polyquaternium-1, poly[oxyethylene (dimethyliminio) ethylene-(dimethyliminio) ethylenedichloride], and a hexamethylene biguanide polymer are added.

The present compositions, which may be multi-purpose solutions, have amultitude of applications, for example, as disinfecting, cleaning,soaking, wetting, rewetting, rinsing, storing, in-the-eye cleaning, andconditioning compositions, for contact lens care, while providingsubstantial lens wearer/user comfort and acceptability. The presentcompositions also increase user compliance, that is promote regular andconsistent contact lens care, and, ultimately, lead to or facilitatebetter ocular health. Any contact lenses, for example, conventional hardcontact lenses, rigid gas permeable contact lenses and soft, hydrophilicor hydrogel, contact lenses, can be treated in accordance with thepresent invention.

Previously, it was believed that the afore-mentioned alkylamine wasinsoluble in aqueous solution, and hence undesirable for use in contactlens-care solutions. The inventors have unexpectedly discovered that theafore-mentioned alkylamines can be made soluble in aqueous solutionswith non-ionic surfactants in an amount that will not neutralize thealkylamine antimicrobial activity. Preferred non-ionic surfactantsinclude any non-ionic surfactants that contain an alkyl chain. Examplesof some non-ionic surfactants for use in the present invention aredisclosed in, for example, Kirk-Othmer, Encyclopedia of ChemicalTechnology, 3rd Edition, Vol. 22 (John Wiley E Sons, 1983), Sislet &Wood, Encyclopedia of Surface Active Agents (Chemical Publishing Co.,Inc. 1964), McCutcheon's Emulsifiers & Detergents, North American andInternational Edition (McCutcheon Division, The MC Publishing Co.,1991), Ash, The Condensed Encyclopedia of Surfactants (ChemicalPublishing Co., Inc., 1989), Ash, What Every Chemical Technologist Wantsto Know About . . . Emulsifiers and Wetting Agents, Vol. 1 (ChemicalPublishing Co., Inc., 1988), Tadros, Surfactants (Academic Press, 1984),Napper, Polymeric Stabilization of Colloidal Dispersion (Academic Press,1983) and Rosen, Surfactants & Interfacial Phenomena, 2nd Edition (JohnWiley & Sons, 1989), all of which are incorporated herein by reference.By way of example, but not of limitation, such surfactants include:Makon® 10 (Stepan Chemical Company, Chicago, Ill.), Lumulse® GR-40(Lambent Technologies Inc., Norcross, Ga.), Lumulse® GRH-40 (LambentTechnologies Inc., Norcross, Ga.), Brij® 72 (Atlas Powder Company,Wilmington, Del.), Brij® 76 (Atlas Powder Company, Wilmington, Del.),Tween™ 80 (Uniquema (ICI Surfactants), Wilmington, Del.), Tween® 40,TPGS™ (Eastman Chemical Co., Kingsport, Tenn.), Cremophor® RH-40 (BASFCorporation, Mount Olive, N.J.), Tetronic®1304 (BASF Corporation, MountOlive, N.J.), Tetronic® 1107 (BASF Corporation, Mount Olive, N.J.),Pluronic® F87 (BASF Corporation, Mount Olive, N.J.).

For example Myristylamine, an alkylamine of the class described above,(“MA”) generally does not dissolve in water or in a basic solution.Furthermore, MA cannot be solubilized in surfactant micelles alone. MAis also insoluble in acid at ambient temperature, even with a solutionpH below 2. However, if an acid and a surfactant which contains an alkylchain coexist in a sufficient surfactant amount and the solution pH isbelow 6, MA may be dissolved in an aqueous solution. Once MA has been sodissolved, the solution pH may be increased, for example by adjustingthe pH of the solution to neutral, without precipitating the MA.

The additional antimicrobial component may be any suitable, preferablyophthalmically acceptable, material effective to disinfect a contactlens contacted with the present solutions or alternatively adequatelypreserve a solution such as a contact lens rewetting solution.Preferably, the additional antimicrobial component is selected frombiguanides, biguanides polymers, salts thereof and mixtures thereof, andis present in an amount in the range of about 0.1 ppm to about 3 ppm orless than 5 ppm (w/v). By way of example, and not of limitation, theadditional antimicrobial component may be a monomeric quaternaryammonium or biguanide compound such as chlorhexidine digluconate,chlorhexidine diacetate, benzethonium chloride andmyristamidopropyldimethylamine. The additional antimicrobial componentmay also be a polymeric quaternary ammonium compound such asPolyquad.RTM. (polyquatemium-1) or poly [oxyethylene (dimethyliminio)ethylene-(dimethyliminio) ethylene dichloride] (sold under the trademarkWSCP by Buckman Laboratories, Inc.). The preferred relatively reducedconcentration of the additional antimicrobial component has been foundto be very effective, in the present compositions, in disinfectingcontact lenses contacted with the compositions, while at the same timepromoting lens wearer/user comfort and acceptability.

Any suitable, preferably ophthalmically acceptable, surfactant componentwhich is effective in cleaning contact lenses may be employed. Thesurfactant component preferably is non-ionic and, more preferably, isselected from poly(oxyethylene)-poly(oxypropylene) block copolymers andmixtures thereof.

Any suitable, preferably ophthalmically acceptable viscosity inducing orthickening agent may be included in the present compositions. Theviscosity inducing component preferably is selected from cellulosicderivatives and mixtures thereof and is present in an amount in therange of about 0.05% or about 1.5% to about 3% or about 5.0% (w/v).Without wishing to limit the invention to any particular theory ofoperation, it is believed that the presence of a viscosity inducingcomponent at least assists in providing the lens wearer/user comfort andacceptability benefits of the present invention, which promote regularand consistent contact lens care and ultimately lead to or facilitatebetter ocular health. The present combinations of components, forexample, including such viscosity inducing components, are effective inproviding the degree of lens wearer/user comfort and acceptabilitybenefits described herein.

Although any suitable, necessarily ophthalmically acceptable, tonicitycomponent may be employed, an extremely useful tonicity component is acombination of sodium chloride and potassium chloride.

The present compositions preferably include an effective amount of achelating component. Any suitable, preferably ophthalmically acceptable,chelating component may be included in the present compositions,although ethylenediaminetetraacetic acid (EDTA), salts thereof andmixtures thereof are particularly effective. More preferably, thepresent compositions include chelating components in effective amountsless than about 0.05% (w/v) and still more preferably 0.02°s (w/v) orless. Such reduced amounts of chelating component in the presentcompositions remain effective in providing the desired chelating and/orsequestering functions while, at the same time, are better tolerated inthe eye, thereby reducing the risk of user discomfort and/or ocularirritation.

Various combinations of two or more of the above noted components may beused in providing at least one of the benefits described herein.Therefore, each and every such combination is included within the scopeof the present invention.

In one embodiment, the present compositions comprise: a liquid aqueousmedium; an alkylamine having the following formula:

where R1 is a C₁₃₋₁₇ alkyl, and R2 and R3 are each independently H or—CH₃, in an amount effective to, in association with the remainder ofthe solution, disinfect a contact lens contacted with the composition; asurfactant, usually a non-ionic surfactant, component in an amounteffective in cleaning a contact lens contacted with the composition; aboric buffer component in an amount effective in maintaining the pH ofthe composition within a physiologically acceptable range; an effectiveamount of a viscosity inducing component; and an effective amount of atonicity component. The present compositions preferably include aneffective amount of a chelating or sequestering component, morepreferably in a range of less than 0.05% (w/v). Each of the components,in the concentration employed, included in the solutions and theformulated solutions of the present invention generally areophthalmically acceptable. In addition, each of the components (in thecase of the alkylamine, in combination with the anionic surfactant asdescribed above), in the concentration employed included in the presentsolutions usually is soluble in the liquid aqueous medium. The solutionmay also optionally include an additional antimicrobial component in anamount effective to, in association with the remainder of the solution,disinfect a contact lens contacted with the composition.

A solution or component thereof is “ophthalmically acceptable” when itis compatible with ocular tissue, that is, it does not cause significantor undue detrimental effects when brought into contact with oculartissue. Preferably, each component of the present compositions is alsocompatible with the other components of the present compositions. Thepresent compositions are more preferably substantially ophthalmicallyoptimized. An ophthalmically optimized composition is one which, withinthe constraints of component chemistry, minimizes ocular response, orconversely delivers ophthalmic benefit to the lens wearing eye.

The presently useful additional antimicrobial components includechemicals which derive their antimicrobial activity through a chemicalor physiochemical interaction with microbes or microorganisms, such asthose contaminating a contact lens. Suitable additional antimicrobialcomponents are those generally employed in ophthalmic applications andinclude, but are not limited to, quaternary ammonium salts used inophthalmic applications such as poly[dimethylimino-2-butene-1,4-diyl]chloride,alpha-[4-tris(2-hydroxyethyl)ammonium]-dichloride (chemical registrynumber 75345-27-6, available under, the trademark Polyquatemium 1® fromOnyx Corporation), benzalkonium halides, and biguanides, such as saltsof alexidine, alexidine-free base, salts of chlorhexidine, hexamethylenebiguanides and their polymers, and salts thereof, antimicrobialpolypeptides, chlorine dioxide precursors, and the like and mixturesthereof. Generally, the hexamethylene biguanide polymers (PHMB), alsoreferred to as polyaminopropyl biguanide (PAPB), have molecular weightsof up to about 100,000. Such compounds are known and are disclosed inOgunbiyi et al, U.S. Pat. No. 4,759,595, the disclosure of which ishereby incorporated in its entirety by reference herein.

Generally, the antimicrobial component is present in the liquid aqueousmedium at an ophthalmically acceptable or safe concentration such thatthe user can remove the disinfected lens from the liquid aqueous mediumand thereafter directly place the lens in the eye for safe andcomfortable wear. Alternatively, the antimicrobial component is presentin the liquid aqueous medium at an ophthalmically acceptable or safeconcentration and sufficient for maintaining preservative effectiveness.The antimicrobial components useful in the present invention preferablyare present in the liquid aqueous medium in concentrations in the rangeof about 0.00001% to about 0.01% (w/v), and more preferably inconcentrations in the range of about 0.00005% to about 0.001% (w/v) andmost preferably in concentrations in the range of about 0.00005% toabout 0.0005% (w/v).

The additional antimicrobial components suitable for inclusion in thepresent invention include chlorine dioxide precursors. Specific examplesof chlorine dioxide precursors include stabilized chlorine dioxide(SCD), metal chlorites, such as alkali metal and alkaline earth metalchlorites, and the like and mixtures thereof. Technical grade sodiumchlorite is a very useful chlorine dioxide precursor. Chlorine dioxidecontaining complexes such as complexes of chlorine dioxide withcarbonate, chlorine dioxide with bicarbonate and mixtures thereof arealso included as chlorine dioxide precursors. The exact chemicalcomposition of many chlorine dioxide precursors, for example, SCD andthe chlorine dioxide complexes, is not completely understood. Themanufacture or production of certain chlorine dioxide precursors isdescribed in McNicholas, U.S. Pat. No. 3,278,447, which is incorporatedin its entirety herein by reference. Specific examples of useful SCDproducts include that sold under the trademark Dura Klor® by Rio LindaChemical Company, Inc., and that sold under the trademark AnthiumDioxide® by International Dioxide, Inc.

If a chlorine dioxide precursor in included in the present compositions,it generally is present in an effective preservative or contact lensdisinfecting amount. Such effective preservative or disinfectingconcentrations usually are in the range of about 0.002 to about 0.06%(w/v) of the present compositions. The chlorine dioxide precursors maybe used in combination with other antimicrobial components, such asbiguanides, biguanide polymers, salts thereof and mixtures thereof.

In the event that chlorine dioxide precursors are employed asantimicrobial components, the compositions usually have an osmolality ofat least about 200 mOsmol/kg and are buffered to maintain the pH withinan acceptable physiological range, for example, a range of about 6 toabout 10.

In one embodiment, the additional antimicrobial component isnon-oxidative. It has been found that reduced amounts of non-oxidativeantimicrobial components, for example, in a range of about 0.1 ppm toabout 3 ppm or less than 5 ppm (w/v), in the present compositions areeffective in disinfecting contact lenses and reduce the risk of suchantimicrobial components causing ocular discomfort and/or irritation.Such reduced concentration of antimicrobial component is very usefulwhen the antimicrobial component employed is selected from biguanides,biguanide polymers, salts thereof and mixtures thereof.

When a contact lens is desired to be disinfected by the presentcompositions, a total amount of antimicrobial component(s) effective todisinfect the lens is used. Generally, such an effective amount of theantimicrobial component reduces the microbial burden or load on thecontact lens by one log order in three hours. More preferably, aneffective amount of the disinfectant reduces the microbial load by onelog order in one hour.

The buffer component is present in an amount effective to maintain thepH of the composition or solution in the desired range, for example, ina physiologically acceptable range of about 6 to about 7.5 or about 8.5.In particular, the solution has a pH in the range of about 7 to about 8.The buffer component preferably includes one or more phosphate ortromethamine (TRIS, 2-amino-2-hydroxymethyl-1,3-propanediol) or boric orboric/sodium borate buffers, for example, combinations of monobasicphosphates, dibasic phosphates and the like, or tromethamine andtromethamine hydrochloride. Particularly useful phosphate buffers arethose selected from phosphate salts of alkali and/or alkaline earthmetals. Examples of suitable phosphate buffers include one or more ofsodium phosphate dibasic (Na₂HPO₄) sodium phosphate monobasic (NaH₂PO₄)and potassium phosphate monobasic (KH₂PO₄). The buffer component mayalso include an amino acid such as taurine. The present buffercomponents frequently are used in amounts in a range of about 0.01% orabout 0.02% to about 0.5% or about 1% (w/v), calculated as phosphateion.

The present compositions usually further comprise effective amounts ofone or more additional components, such as a detergent or surfactantcomponent; a viscosity inducing or thickening component; a chelating orsequestering component; a tonicity component; and the like and mixturesthereof. The additional component or components may be selected frommaterials which are known to be useful in contact lens care compositionsand are included in amounts effective to provide the desired effect orbenefit. When an additional component is included, it is generallycompatible under typical use and storage conditions with the othercomponents of the composition. For instance, the aforesaid additionalcomponent or components are substantially stable in the presence of theantimicrobial and buffer components described herein.

A surfactant component generally is present in an amount effective incleaning, that is to at least facilitate removing, and preferablyeffective to remove, debris or deposit material from, a contact lenscontacted with the surfactant containing solution. Exemplary surfactantcomponents include, but are not limited to, non-ionic surfactants, forexample, polysorbates (such as polysorbate 20-Trademark Tween 20),4-(1,1,3,3-tetramethylbutyl)phenol/poly(oxyethylene) polymers (such asthe polymer sold under the trademark Tyloxapol),poly(oxyethylene)-poly(oxypropylene) block copolymers, glycolic estersof fatty acids and the like, and mixtures thereof.

The surfactant component is generally non-ionic, and usually is selectedfrom poly(oxyethylene)-poly(oxypxopylene) block copolymers and mixturesthereof. Such surfactant components can be obtained commercially fromthe BASF Corporation under the trademarks Pluronic® and Tetronic®. Suchblock copolymers can be generally described aspolyoxyethylene/polyoxypropylene condensation polymers terminated inprimary hydroxyl groups. They may be synthesized by first creating ahydrophobe of desired molecular weight by the controlled addition ofpropylene oxide to the two hydroxyl groups of propylene glycol orglycerin. In the second step of the synthesis, ethylene oxide is addedto sandwich this hydrophobe between hydrophile groups.

In accordance with a more preferred embodiment of the invention, suchblock copolymers having molecular weights in the range of about 2500 to30,000 daltons are suitable, with a molecular weight range of about 6000to about 15,000 daltons being still more preferred. Specific examples ofsurfactants which are satisfactory include: poloxamer 108 (BASFCorporation, Mount Olive, N.J.), poloxamer 188, poloxamer 237, poloxamer238, poloxamer 288, poloxamer 407, Tetronic 1107, Tetronic 1304,Tetronic 1307. Particularly good results are obtained poloxamer 237.

The amount of surfactant component, if any, present varies over a widerange depending on a number of factors, for example, the concentrationof the alkylamine being used, the specific surfactant or surfactantsbeing used, the other components in the composition and the like. Oftenthe amount of surfactant is in the range of about 0.005% or about 0.01%to about 0.1% or about 0.5% or about 1.0% (w/v).

The viscosity inducing components employed in the present solutionspreferably are effective at low or reduced concentrations, compatiblewith the other components of the present solutions, and anionic. Suchviscosity inducing components are effective to enhance and/or prolongthe cleaning and wetting activity of the surfactant component and/orcondition the lens surface rendering it more hydrophilic (lesslipophilic) and/or to act as a demulcent on the eye. Increasing thesolution viscosity provides a film on the lens which may facilitatecomfortable wearing of the treated contact lens. The viscosity inducingcomponent may also act to cushion the impact on the eye surface duringinsertion and serves also to alleviate eye irritation.

Suitable viscosity inducing components include, but are not limited to,water soluble natural gums, cellulose-derived polymers and the like.Useful natural gums include guar gum, gum tragacanth and the like.Useful cellulose-derived viscosity inducing components includecellulose-derived polymers, such as hydroxypropyl cellulose,hydroxypropylmethyl cellulose, carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose and the like. More preferably, theviscosity inducing agent is selected from cellulose derivatives(polymers) and mixtures thereof. A very useful viscosity inducingcomponent is hydroxypropylmethyl cellulose (HPMC).

The viscosity inducing component is used in an amount effective toincrease the viscosity of the solution, preferably to a viscosity in therange of about 1.5 to about 30, or even as high as about 750, cps at 25°C., preferably as determined by USP test method No. 911 (USP 23, 1995).To achieve this range of viscosity increase, an amount of viscosityinducing component of about 0.01% to about 5% (w/v) preferably isemployed, with amounts of about 0.05% to about 0.5% being morepreferred.

A chelating or sequestering component preferably is included in anamount effective to enhance the effectiveness of the antimicrobialcomponent and/or to complex with metal ions to provide more effectivecleaning of the contact lens.

A wide range of organic acids, amines or compounds which include an acidgroup and an amine function are capable of acing as chelating componentsin the present compositions. For example, nitrilotriacetic acid,diethylenetriaminepentacetic acid, hydroxyethylethylenediaminetriaceticacid, 1,2-diaminocyclohexane tetraacetic acid, hydroxyethylaminodiaceticacid, ethylenediamine-tetraacetic acid and its salts, polyphosphates,citric acid and its salts, tartaric acid and its salts, and the like andmixtures thereof, are useful as chelating components.Ethylenediaminetetraacetic acid (EDTA) and its alkali metal salts, arepreferred, with disodium salt of EDTA, also known as disodium edetate,being particularly preferred.

The chelating component preferably is present in an effective amount,for example, in a range of about 0.01% and about 1% (w/v) of thesolution.

In a very useful embodiment, particularly when the chelating componentis EDTA, salts thereof and mixtures thereof, a reduced amount isemployed, for example, in the range of less than about 0.05% (w/v) oreven about 0.02% (w/v) or less. Such reduced amounts of chelatingcomponent have been found to be effective in the present compositionswhile, at the same time, providing for reduced discomfort and/or ocularirritation.

The liquid aqueous medium used is selected to have no substantialdeleterious effect on the lens being treated, or on the wearer of thetreated lens. The liquid medium is constituted to permit, and evenfacilitate, the lens treatment or treatments by the presentcompositions. The liquid aqueous medium advantageously has an osmolalityin the range of at least about 200-mOsmol/kg to about 300 or about 350mOsmol/kg. The liquid aqueous medium more preferably is substantiallyisotonic or hypotonic (for example, slightly hypotonic) and/or isophthalmically acceptable.

The liquid aqueous medium preferably includes an effective amount of atonicity component to provide the liquid medium with the desiredtonicity. Such tonicity components may be present in the liquid aqueousmedium and/or may be introduced into the liquid aqueous medium. Amongthe suitable tonicity adjusting components that may be employed arethose conventionally used in contact lens care products, such as variousinorganic salts. Sodium chloride and/or potassium chloride and the likeare very useful tonicity components. The amount of tonicity componentincluded is effective to provide the desired degree of tonicity to thesolution. Such amount may, for example, be in the range of about 0.1% toabout 1.5% (w/v). If a combination of sodium chloride and potassiumchloride is employed, it is preferred that the weight ratio of sodiumchloride to potassium chloride be in the range of about 2.5 to about 6or about 8.

The amount of taurine useful in the present invention may be determinedby objective clinical measures such as tear LDH release from cornealepithelial cells or fluorescein barrier permeability measurements oranother means to evaluate ocular cell membrane integrity such asfluorescein or rose bengal staining. Yet another means to evaluateocular cell membrane integrity is the use of confocal microscopy tomeasure epithelial cell area. In lieu of using tear LDH as a responsefactor, another inflammatory mediator may be measured in tears toindicate a beneficial effect from taurine. Useful amounts of taurine canalso be determined by subjective clinical measures such as itching,lacrimation (tearing) and comfort. The amount of taurine useful in thepresent invention is generally from about 0.01 to about 2.0 w/v %. Thepreferred amount is 0.05 to 1.00 w/v %.

Methods for treating a contact lens using the herein describedcompositions are included within the scope of the invention. Suchmethods comprise contacting a contact lens with such a composition atconditions effective to provide the desired treatment to the contactlens.

The contacting temperature is preferred to be in the range of about 0°C. to about 100° C., and more preferably in the range of about 10° C. toabout 60° C. and still more preferably in the range of about 15° C. toabout 30° C. Contacting at or about ambient temperature is veryconvenient and useful. The contacting preferably occurs at or aboutatmospheric pressure. The contacting preferably occurs for a time in therange of about 5 minutes or about 1 hour to about 12 hours or more.

The contact lens can be contacted with the liquid aqueous medium byimmersing the lens in the medium. During at least a portion of thecontacting, the liquid medium containing the contact lens optionally maybe agitated, for example, by shaking the container containing the liquidaqueous medium and contact lens, to at least facilitate removal ofdeposit material from the lens. After such contacting step, the contactlens optionally may be manually rubbed to remove further depositmaterial from the lens. The cleaning method optionally may also includerinsing the lens substantially free of the liquid aqueous medium priorto returning the lens to a wearer's eye.

The following examples, while not limiting, are illustrative of theinvention.

The following is the procedure by which various antimicrobial agents andsolutions are tested for their ability to reduce microbial loads overshort periods of time, typically 24 hours and less. The procedure is abasic microbiology challenge test, which involves the inoculation oftest product aliquots with a known number of viable cells of severaltest organisms, and assay for the survivors at various time intervals.The results are used to calculate log drops at soak times and constructkill-curves (graphs of survivors versus time) if desired.

Candida albicans, ATCC 10231, is one of five organisms specified per FDAand ISO/CLI tests for the testing of contact lens disinfectants (FDAPremarket Notification (510k) Guidance Document for Contact Lens CareProducts, Appendix B, Apr. 1, 1997 and ISO/FDIS 14729: Ophthalmicoptics-Contact lens care products-Microbiological requirements and testmethods for products and regimens for hygienic management of contactlenses, January 2001). Contact lens disinfectants are also known ascontact lens multi-purpose solutions when they are used for rinsing,cleaning, disinfection, storage and rewetting contact lenses. The fiveFDA/ISO specified test organisms are listed below:

Serratia marcescens, ATCC 13880

Staphylococcus aureus, ATCC 6538

Pseudomonas aeruginosa, ATCC 9027

Candida albicans, ATCC 10231

Fusarium solani, ATCC 36031

Candida albicans is often the most resistant of the five organisms tocommonly used cationic antimicrobial agents in contact lensmulti-purpose solutions. Thus, achievement of adequate antimicrobialactivity against Candida is often the most difficult task to pass aparticular disinfection efficacy standard. FDA and ISO guidelinesspecify two disinfection efficacy standards, indicated in the tablebelow:

Stand Alone Disinfectant (Primary) Criteria:

Average log reduction Organism at labeled soak time S. marcescens 3.0logs S. aureus 3.0 logs P. aeruginosa 3.0 logs C. albicans 1.0 log F.solani 1.0 log

Regimen-Dependent Disinfectant (Secondary) Criteria:

Organism Average log reduction at labeled soak time S. marcescensMinimum of 1.0 log per bacterium, S. aureus sum of all three bacterialog-drops P. aeruginosa must be greater than or equal to 5.0 log C.albicans Stasis F. solani Stasis

The specific test procedure for testing antimicrobial activity againstthe five FDA/ISO specified test organisms is as follows (C. albicans isprovided as a specific example): Test samples are sterile-filteredthrough a 0.22 micron sterile filter into sterile plastic high densitypolyethylene bottles or plastic flasks. A 10-mL aliquot of test sampleis aseptically transferred into a sterile polystyrene plastic test tube.Sterile saline (0.90 w/v % NaCl) with 0.05 w/v % Polysorbate 80(SS+TWEEN) is transferred into a separate control tube. All samples andcontrol are stored at 20–25° C. throughout the duration of the test.

Test cultures of Candida albicans, ATCC 10231 are prepared in theconventional manner. Candida albicans cultures are grown on agar slantsfrom primary frozen, lyophilized or “Culti-loop®” cultures. Three mL ofsterile 0.9% saline is used to gently dislodge culture growth from theagar surface. The resulting harvest is transferred to an appropriatescrew cap test tube containing glass beads and vortexed forapproximately one minute. The vortexed harvest is diluted as needed withsterile 0.9% saline to prepare the culture inoculum with a concentrationof 1×10e8 CFU/mL. Fifty microliters of culture inoculum is added to 10.0mL of each test sample and control, so that the final inoculum level isin the range of 1×10e5 to 1×10e6 CFU(colony forming units) per mL ofCandida albicans, ATCC 10231. Each sample and control tube is vortexedbriefly to disperse the inoculum. Contact time intervals for testingactivity against Candida are typically 4 or 6 hours, to conform to theintended product label instructions for contact lens soak time.

Aerobic Plate Count Methods are performed in order to quantitate testsamples for their levels of survivors. At appropriate assay times, 0.5mL well-vortexed aliquots are removed from sample tubes and added toglass test tubes containing 4.5 mL Letheen Neutralizing Broth media(Berton, Dickinson and Company, Sparks, Md.). After a previouslydetermined, validated neutralizing time period, these samples arediluted 10-fold through serial dilutions using glass test tubescontaining 4.5 mL Letheen Neutralizing Broth media. Aliquots of 0.1 mLare removed from each dilution tube and spread-plate applied to agarplates containing Sabouraud Dextrose Agar (SAB)(Berton, Dickinson andCompany, Sparks, Md.). 10¹ to 10⁴ CFU/mL survivor levels arequantitated. The SS+TWEEN control samples are quantitated only at time=0using 3 serial 10-fold dilutions, in order to determine the actuallevels of challenge organisms initially present per mL of sample(initial inoculum). Recovery agar plates are incubated at 20–25° C. for3–5 days.

Numbers of colony-forming-units (CFU) are counted for each countableagar plate (generally between 8–80 colonies per plate for Candidaplates). Log-drops in CFU/mL are determined for each sample at each timeinterval by converting the total number of survivors at each timeinterval to a base-10 logarithm and subtracting this from the base-10logarithm equivalent of the initial inoculum of the SS+TWEEN control.Log reduction values can be plotted against contact time (the particulartest time interval) or evaluated as is.

EXAMPLE 1

As noted above in the Background of the Invention section, non-ionicsurfactants are commonly used in microbiology tests to stop a quaternaryammonium/alkylamine activity. One of the significant differences betweencontact lens care system and re-circulating water systems is that theformer requires the presence of a large amount of a surfactant as acleaning agent while the latter is not compatible with surfactants dueto foaming problems. Anionic surfactant and polymeric/non-polymericquaternary ammoniums form ion-pair or precipitate in an aqueous solutionand therefore, cannot be mixed together. The presence of non-ionicsurfactant at a cleaning agent level usually would cause a significant,if not complete, loss of antimicrobial activity for non-polymericquaternary ammonium or alkylamine. As shown in Table 1, the addition ofthe non-ionic surfactant tocopherol polyethylene glycol succinate(“TPGS”) halts the ammonium/alkylamine activity.

TABLE 1 Formulation w/v % w/v % Cetylpyridinium Chloride 0.001 0.001TPGS 0 0.025 Taurine 0.05 0.05 Propylene Glycol 0.50 0.50 Tetronic ®1307 0.05 0.05 NaEDTA 0.01 0.01 HPMC 0.15 0.15 Tris 0.021 0.021 Tris.HCl0.055 0.055 NaCl 0.65 0.65 KCl 0.14 0.14 Log Drop Log Drop C. albicans4.41 0.12 F. solani >4.08 1.06

EXAMPLE 2

The formulations shown in Table 2A were evaluated for theirantimicrobial activity for contact lens disinfecting. As may be seen,this formulation exhibited a very high antimicrobial activity.

TABLE 2A Ingredient % w/w % w/w Myristylamine 0.0003 0.0005 Tetronic ®1307 0.05 0.05 HPMC 0.15 0.15 Propylene Glycol 0.5 0.5 Tris 0.021 0.021Tris.HCl 0.055 0.055 NaCl 0.65 0.65 KCl 0.14 0.14 pH 7.8 Log Drop LogDrop S. marcescens 1.18 2.6 S. aureus 2.87 4.8 P. aeruginosa >4.63 >4.63C. albicans 3.67 4.41 F. solani >4.34 >4.34

It is easily seen from the data in Table 2 that the myristylamine hasstrong antimicrobial activity against C. albicans, as well as otherorganisms.

In contrast as shown in Table 2B, Dodecylamine, a C12 primary aminewhich is water soluble, has very weak antimicrobial activity and,therefore, not suitable as a disinfectant for contact lens cleaning anddisinfecting.

TABLE 2B Ingredient % w/w % w/w Dodecylamine 0.0005 0.0003 Taurine 0.050.05 Propylene Glycol 0.50 0.50 Tetronic 1307 0.05 0.05 NaEDTA 0.01 0.01HPMC 0.15 0.15 Tris 0.021 0.021 Tris.HCl 0.055 0.055 NaCl 0.65 0.65 KCl0.14 0.14 pH 7.8 Log drop Log drop S. marcesens 0.46 0.46 S. aureus 0.120.34 P. aeruginosa 1.36 1.4 C. albicans 1.77 0.91 F. solani 0.16 0.09

EXAMPLE 3

As shown by the formulations and resulting log reductions shown in Table3, the antimicrobial activity of an alkylamine having the followingformula:

where R1 is a C₁₃₋₁₇ alkyl, and R2 and R3 are each independently H or—CH₃, may be further enhanced if one or more other types ofantimicrobial agents are added.

TABLE 3 Formulation w/v % w/v % Myristylamine 0.0005 0.0005 WSCP 0.0010.0 NaClO₂ 0.01 0.0 NaCitrate 0.4 0.0 Taurine 0.05 0.05 Propylene Glycol0.50 0.50 T1307 0.05 0.05 HPMC 0.15 0.15 Tris 0.021 0.021 Tris.HCl 0.0550.055 NaCl 0.65 0.65 KCl 0.14 0.14 Log Drop Log Drop S. marcescens 3.11.68 S. aureus 3.74 2.93 P. aeruginosa >4.63 >4.63 C. albicans 2.95 3.29F. solani >4.34 >4.34

These results are collaborated by the formulation and resulting logreductions shown in Table 4, and by the formulations and resulting logreductions shown in Table 5.

TABLE 4 Formulation w/v % w/v % Myristylamine 0.0003 0.0003 PHMB 00.00003 Taurine 0.05 0.05 Propylene Glycol 0.50 0.50 Tetronic 1107 0.050.05 HPMC 0.15 0.15 Tris 0.021 0.021 Tris.HCl 0.055 0.055 NaCl 0.65 0.65KCl 0.14 0.14 pH 7.8 Log Drop Log Drop S. marcescens 1.18 3.46 S. aureus2.87 4.21 P. aeruginosa >4.63 >4.63 C. albicans 3.67 3.31 F.solani >4.34 >4.34

TABLE 5 Formulation w/v % Myristylamine 0.0005 Polyquaternium-1 0.001NaCitrate 0.6 Taurine 0.05 Propylene Glycol 0.50 Tetronic ® 1304 0.05HPMC 0.15 Tris 0.021 Tris.HCl 0.055 NaCl 0.65 KCl 0.14 pH 7.8 Log DropS. marcescens 3.64 S. aureus 4.69 P. aeruginosa >4.63 C. albicans 4.52F. solani >4.34

EXAMPLE 4

As discussed in greater detail above, the inventors have discovered thata certain type of non-ionic surfactants (certain mixing ratios) candissolve these water insoluble alkylamines while maintaininganti-microbial effectiveness for disinfection. Specifically, waterinsoluble alkylamines having the following formula,

where R1 is a C₁₃₋₁₇ alkyl, and R2 and R3 are each independently H or—CH₃, may be dissolved in aqueous solution without neutralization of theantimicrobial activity by the surfactant. The maximumsurfactant:antimicrobial ratio above which the antimicrobial activitieswill be significantly neutralized varies depending on thehydrophobicity/hydropholicity of the surfactant and the amount of theantimicrobial. For an ordinary surfactant with at least one alkyl chain,such as Tween 80 and TPGS, this maximum surfactant:antimicrobial ratiois about 7–20 when the alkylamine concentration is not more than 10 ppm.One of ordinary skill in the art can determine the maximumsurfactant:alkylamine ratio for other surfactant systems based on thedisclosure contained herein.

Table 6 shows that the 10 ppm MA solutions fail to meet the stand-alonecriteria when the Tween 80:MA ratio is at 7.4. For TPGS, the maximumsurfactant:MA ratio is about 20 (see Table 8). However, with theaddition of a second antimicrobial, Polyquaternium-1, the solution canstill be a stand-alone disinfectant product.

TABLE 6 Formulation % w/w % w/w Tween 80 0.0074 0.0074 Myristylamine0.001 0.001 Polyquaternium-1 0 0.000075 Taurine 0.05 0.05 PropyleneGlycol 0.5 0.5 Tetronic ® 1307 0.05 0.05 Na₂EDTA 0.01 0.01 HPMC 0.150.15 Na₂HPO₄.7H2O 0.12 0.12 NaH₂PO₄.H2O 0.01 0.01 NaCl 0.55 0.55 KCl0.14 0.14 pH 7.3 Log drop at 6 hour S. marcescens 36031 1.19 3.12 S.aureurs 6538 1.04 3.21 P. aeruginosa 9027 >4.58 >4.58 C. albicans10231 >4.67 >4.67 F. solani 36031 3.73 3.12

However, when the surfactant and alkylamine are present in a ratio of20, anti-fungal activity is not so reduced. Solution #5 shown in Table 7(compared with solution #6 that only differs in the TPGS content)contains surfactant and alkylamine in a ratio of (TPGS:MA) of 20. Asshown in Table 7, when the surfactant:alkylamine ratio is 20,anti-fungal activity (Ca and Fs) remains.

TABLE 7 #5 #6 Formulation w/v % w/v % Myristylamine 5 ppm 5 ppm TPGS0.01 0 Taurine 0.05 0.05 Propylene Glycol 0.50 0.50 Tetronic ® 1307 0.050.05 NaEDTA 0.01 0.01 HPMC 0.15 0.15 Tris 0.021 0.021 Tris.HCl 0.0550.055 NaCl 0.65 0.65 KCl 0.14 0.14 pH 7.8 Log Drop Log Drop S. marcesens0.99 2.6 S. aureus 2.57 4.8 P. aeruginosa 4.86 4.86 C. albicans 4.414.41 F. solani 2.5 3.43

Furthermore, as shown in Table 8A, the anti-fungal activity (Ca and Fs)was still seen at the TPGS:MA ratio of up to 60. However, theanti-bacteria activity lost considerably at the TPGS:MA ratio of 40.Thus, one of ordinary skill in the art may carefully tailor the solutionto the desired antimicrobial activity. Such tailoring may be achieved,for example, by controlling the alkylamine content or by addingadditional antimicrobials into solution.

TABLE 8A #3 #2 #4 Formulation % w/w % w/w % w/w Myristylamine 0.0010.001 0.001 TPGS 0.06 0.04 0.02 Taurine 0.05 0.05 0.05 Propylene Glycol0.50 0.50 0.50 Tetronic ® 1307 0.05 0.05 0.05 NaEDTA 0.01 0.01 0.01 HPMC0.15 0.15 0.15 Tris 0.021 0.021 0.021 Tris.HCl 0.055 0.055 0.055 NaCl0.65 0.65 0.65 KCl 0.14 0.14 0.14 pH 7.8 Log Drop Log Drop Log Drop S.marcesens 0.46 0.67 2.2 S. aureus 0.22 1.31 4.5 P. aeruginosa 2.32 3.724.26 C. albicans 3.72 4.41 4.41 F. solani 2.76 2.52 3.73

As shown in Table 8B, the surfactant:antimicrobial ratio can be morethan 500 when surfactant is a Tetronic® or Pluronic®. Such ratio may beexplained, perhaps, by the fact that neither of these surfactantscontain an alkyl chain.

TABLE 8B % w/w % w/w % w/w % w/w Cetylamine 0.0001 0.0001 0.0001250.0003 PHMB 0.00 0.00002 0.00 0.00 Boric acid 0.6 0.6 0.6 0.6 NaCl 0.590.59 0.59 0.59 HPMC 0.15 0.15 0.15 0.15 Edetate Disodium 0.01 0.01 0.010.01 Taurine 0.05 0.05 0.05 0.05 NaCl 0.59 0.59 0.59 0.59 KCl 0.14 0.140.14 0.14 Pluronic ® F87 0.05 0.05 0.05 0.05 PEG 400 0.2 0.2 0.2 0.2NaOH adjust pH to 7.7 Log Drop Log Drop Log Drop Log Drop S. marcescens13880 2.35 4.18 3.76 3.61 S. aureus 6538 4.18 4.81 4.81 4.79 P.aeruginosa 9027 4.49 4.43 3.95 4.49 C. albicans 10231 2.89 1.51 1.972.89 F. solani 36031 1.3 1.14 2.76 1.48

EXAMPLE 5

Another benefit of the present invention that has been discovered by theinventors is that alkylamines having the following formula:

where R1 is a C₁₃₋₁₇ alkyl, and R2 and R3 are each independently H or—CH₃, have a significantly lower contact lens uptake than other types ofquaternary ammonium or tertiary amines. As a result, eye irritation canbe significantly reduced.

The results in Table 9A show the remaining quaternary ammonium andtertiary amine content left in solution after a 15 ml-solution-2 lensesclosed system has been shaken for 6 days at room temperature. The“Without Lens” column shows the remaining quaternary ammonium andtertiary amine content left in solution after the identical 15 ml-system(minus the lenses) was shaken under identical conditions. The controlwhich was run for this experiment, which includes the remainingingredients in the solutions referenced in Table 9A are listed in Table9B. As one of ordinary skill in the art would realize, the lessquaternary ammonium or tertiary amine content remaining in solutionafter the shaking period, the higher the absorption by the lenses.

TABLE 9A Without Lens Acuvue Purevision Armeen 12D 44.4 ppm 35.0 ppm14.1 ppm (Dodecylamine) Myristylamine, 37.9 ppm 34.1 ppm 13.0 ppm (TPGS20 fold) Myristylamidopropyl- 43.5 ppm 18.2 ppm 4.7 ppm dimethylamineCetylpyridium 42.7 ppm 3.3 ppm 1.3 ppm chloride

TABLE 9B Placebo for the solutions in Table 9a % w/w Taurine 0.05Propylene Glycol 0.50 T1307 0.05 HPMC 0.15 Tris 0.021 Tris.HCl 0.055NaCl 0.65 KCl 0.14 D.I water 98.38 pH 7.8

The solutions according to the above examples may be used, for example,to clean contact lenses. In this embodiment of the invention,approximately three (3) ml of this solution is introduced into a lensvial containing a lipid, oily deposit laden, hydrophilic or soft contactlens. The contact lens is maintained in this solution at roomtemperature for at least about four (4) hours. This treatment iseffective to disinfect the contact lens. In addition, it is found that asubstantial portion of the deposits previously present on the lens hasbeen removed. This demonstrates that this solution has substantialpassive contact lens cleaning ability. Passive cleaning refers to thecleaning which occurs during soaking of a contact lens, withoutmechanical or enzymatic enhancement.

After this time, the lens is removed from the solution and is placed inthe lens wearer's eye for safe and comfortable wear. Alternately, afterthe lens is removed from the solution, it is rinsed with anotherquantity of this solution and the rinsed lens is then placed in the lenswearer's eye for safe and comfortable wear.

Alternatively, the solutions provided in the above-referenced examplesmay be used, for example, to wet or rewet contact lenses. A hydrophiliccontact lens is ready for wear. In order to facilitate such wearing, oneor two drops of one of the above solutions is placed on the lensimmediately prior to placing the lens in the lens wearer's eye. Thewearing of this lens is comfortable and safe.

Alternatively, a lens wearer wearing a contact lens may apply one or twodrops of one of the above solutions in the eye wearing the lens. Thiseffects a re-wetting of the lens and provides for comfortable and safelens wear.

While this invention has been described with respect to various specificexamples and embodiments, it is to be understood that the invention isnot limited thereto and that it can be variously practiced within thescope of the following claims.

1. A multi-purpose solution for contact lenses comprising: an aqueousliquid medium; from about 0.1 ppm to about 10 ppm of an alkylamine

where R1 is a C₁₃₋₁₇ alkyl and R2 and R3 are each independtly H or CH₃;the alkylamine comprises a C₁₃₋₁₇ alkyl; and a non-ionic surfactant thatis present in the solution in an amount effective to (a) render thealkylamine soluble in the aqueous solution without neutralizing thealkylamine antimicrobial activity effect and (b) to clean a contact lenscontacted with said solution.
 2. The solution as in claim 1, wherein thealkylamine is selected from the group consisting of myristylamine andcetylamine.
 3. The solution as in claim 1, wherein the non-ionicsurfactant is a polyoxypropylenepolyoxyethylene co-block polymer.
 4. Thesolution as in claim 1, further comprising a second antimicrobialcomponent.
 5. The solution as in claim 1, further comprising a viscosityinducing component selected from the group consisting of cellulosicderivatives and mixtures thereof in the range of about 0.05% to about5.0% (w/v) of the total solution.
 6. The solution as in claim 1, furthercomprising a chelating component in an amount of less than 0.05% (w/v)of the total solution.
 7. The solution as in claim 1, further comprisinga tonicity component in an amount effective in providing the desiredtonicity to the solution.
 8. The solution as in claim 1, furthercomprising a buffer component in an amount effective in maintaining thepH of said solution within a physiologically acceptable range.
 9. Amulti-purpose solution for contact lens care comprising: an aqueousliquid medium; from about 0.1 ppm to about 10 ppm of a firstantimicrobial component in an amount effective to disinfect a contactlens contacted with said solution, the antimicrobial componentcomprising an alkylamine

where R1 is a C₁₃₋₁₇ alkyl and R2 and R3 are each independtly H or CH₃;a non-ionic surfactant that is present in the solution in an amounteffective to (a) render the alkylamine soluble in the aqueous solutionwithout neutralizing the alkylamine antimicrobial activity and (b) toclean the contact lens contacted with said solution; a buffer componentin an amount effective in maintaining the pH of said solution within aphysiologically acceptable range; a viscosity inducing componentselected from the group consisting of cellulosic derivatives andmixtures thereof in the range of about 0.05% to about 5.0% (w/v) of thetotal solution; a chelating component in an amount of less than 0.05%(w/v) of the total solution; and a tonicity component in an amounteffective in providing the desired tonicity to said solution.
 10. Thesolution as in claim 9, wherein the alkylamine is selected from thegroup consisting of myristylamine and cetylamine.
 11. The solution as inclaim 9, wherein the non-ionic surfactant is apolyoxypropylenepolyoxyethylene co-block polymer.
 12. The multi-purposesolution of claim 9, further comprising a second antimicrobialcomponent.
 13. The multi-purpose solution of claim 12, wherein theantimicrobial component is selected from the group consisting ofbiguanides, biguanide polymers, monomeric quaternary ammonium compound,salts thereof and mixtures thereof.
 14. The multi-purpose solution ofclaim 12, wherein the second antimicrobial component is present in anamount ranging from about 0.1 ppm to about 3 ppm.
 15. The multi-purposesolution of claim 9, wherein the non-ionic surfactant is selected fromthe group consisting of poly (oxyethylene)-poly(oxypropylene) blockcopolymers and mixtures thereof, and is present in an amount in a rangeof about 0.01% to about 1.0% (w/v).
 16. The multi-purpose solution ofclaim 9, wherein the non-ionic surfactant is present in an amount in therange of about 0.01% to about 1.0% (w/v).
 17. The multi-purpose solutionof claim 9, wherein the buffer component includes boric acid.
 18. Themulti-purpose solution of claim 9, wherein the buffer component ispresent in an amount in a range of about 0.01% to about 1% (w/v). 19.The multi-purpose solution of claim 9, wherein the viscosity inducingcomponent is hydroxypropylmethyl cellulose.
 20. The multi-purposesolution of claim 9, wherein the tonicity component includes acombination of sodium chloride and potassium chloride and is present ina range of about 0.4% to about 1.5% (w/v).
 21. The multi-purposesolution of claim 9, wherein the chelating component is EDTA.
 22. Themulti-purpose solution of claim 9, further comprising taurine.
 23. Amulti-purpose solution for contact lenses comprising: an aqueous liquidmedium; from about 0.1 ppm to about 10 ppm of a first antimicrobialagent comprising an alkylamine

where R1 is a C₁₃₋₁₇ alkyl and R2 and R3 are each independtly H or CH₃;a second antimicrobial agent; a non-ionic surfactant that is present inthe solution in an amount effective to render the alkylamine soluble inthe aqueous solution without neutralizing the alkylamine antimicrobialactivity; and taurine in an amount effective to protect ocular tissuecell membranes.